Regulator system for condenser circulating pumps



H. F. SCHMIDT REGULATOR SYSTEM FOR CONDENSER CIRCULATING PUMPS Filed Dec. 5. 1920 ATTORNEY Patented May 31, 1927.

UNITED STATES PATENT OFFICE.

HENRY F: SCHMIDT, F SWARTHMORE, PENNSYLVANIA, ASSIGNOR T O WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

REGULATOR SYSTEM FOR CONDENSER CIRCULATING PUMPS.

Application filed December 3, 1920. Serial No. 427,995.

My invention relates to automatic regulating devices for pumps and more particularly to regulators for that class of pumps especially adapted to circulate cooling fluid through the tubes of surface condensers and the like.

The object of my invention is to produce apparatus of the character designated which shall be responsive to variations of pressure within the condenser and which shall cause cooling water to pass through the condenser I 1n ramounts requisite to maintaln thereln substantially a predetermined degree of vacuum. 0

I attain this object by means of the pres: sure-responsive motor device illustrated in the accompanying drawing which is a diagrammatic view of an apparatus embodying a preferred form of my invention.

The pressure maintained within a condenser is usually about 28 inches of vacuum or about 1 pound absolute. It is advantageous to maintain this condition within a condenser to insure proper condensation of the exhaust steam as from a turbine unit. In accordance with my construction, I secure the desired condenser conditions by controlling the capacity of a circulating pump in response to pressure variations, within the condenser. Furthermore, I provide means whereby if the pump auxiliaries fail or if the condenser tubes become partially clogged, approximation to normal operating conditions is maintained,-in so far as is possible without undue racing of the circulating pump. While I have illustrated a propeller pump arranged to circulate water through the tubes of a condenser in the usual manner, it is obvious that any other type of circulating pump may be used, although I have found that the arrangement shown in the drawing is reliable and efficient.

Referring to the drawing for a more detailed understanding of my invention, I indicate a circulating pump of the propeller type comprising a propeller 11 mounted within a pump casing 12. The circulating pump 10 may be of any type whatsoever and is not necessarily limited to the propeller type. Cooling water is admitted to the pump .10; through an inlet 13, and discharged through an outlet 14. and through a conduit 15 to a condenser 16, from which it is discharged through any convenient outlet. The propeller 11 is driven by means of a turbine 18 connected thereto as by a shaft 19. Motive fluid for the turbine 18 issupplied through a conduit 20, the supply being controlled by means of a throttle valve 21 which is actuated by a device responsiveto variations in the absolute pressure within the condenser and to the pressure exerted by the pump, as will hereinafter be more fully set forth.

I employ two pressure-responsive diaphragm motors 22 and 23 which are cooperatively associated toefl'ect. the opening and closing of the valve 21, the diaphragm motor 22 being responsive to variations of pressure in the cooling water and to variations in speed of the pump, and the motor 23 being responsive to variationsin the absolute pressure within the condenser, and to variations in-the atmospheric pressure.

The pressure motor 22 comprises a diaphragm 245 and two ressure chambers 25 and 26. The pressure-chamber 25 receives fluid under pressure i through a conduit 27 from a small centrifugal pump 26, which,

is mounted within the pump casing 12 on thepump shaft 19. The pressure chamber 26 communicates with the discharge outlet 14 of the circulating pump'10 through a conduit 28. The diaphragm 24is connected to a rod 29 which serves as a stem to operate the balanced throttle valve 21.

The pressure-responsive motor 23 is divided by a diaphragm 30 into two pressure chambers 31 and 32. The pressure chamber 31 communicates with through a conduit 34, and the pressure chamber 32 communicates with the interior of the condenser through a conduit 33. The motor 23 is preferably so aligned with the motor 22 that the rod 29 may pass centrally through and be secured to the diaphragm 30.

Located within the chamber 32 of the pressure-responsive motor 23 j is a helical spring v35 which bears against the diaphragm 30 and the casingwith a predetermined pressure for constant conditions in the opera tion of the regulating device.

Having thus described the relation of the several parts, the operation of the governing device is as follows;

the atmosphere and the turbine 18 rotates the pump Assume that under normal operation of the apparatus the pressure within the condenser 16 is substantially one pound absolute the propeller 11"at 5000 R. P. M. If an increased amount'of steam is delivered to the condenser, a pressure is built up Within the condensing space and this increase'in.

the turbine 18. 'The flow of the cooling 'water is thereby decreased to an amount sufficient for a normal load.

Under certain conditions of operation, the pressure within the condenser may continue to increase, due either to a failure of the air or condensate pump or to other causes. The pressure would then build up in the chamber 32, opening the valve 21 more Widely, under which conditions there would be a tendency for the circulating pump to race.

In manyjnstances the pressure contlnues to mcrease 1n the condenser and the requisite amount of cooling water cannot be supplied to reduce the increasing pressure. For this reason, I rovide a governing arrangement whereby t e predetermined speed of the circulating apparatus cannot be exceeded. The governing action is effected by the second pressure-responsive device 22. In normal operation the difference in pressure existing between the conduits 27 and 28' is relatively small butif the propeller is rotated at an excessive or dangerous speed the pumping action of the auxiliary pump 26 causes the diaphragm 24 to move to counteract the motion of the diaphragm 30 and therefore keeps the pumping apparatus operating within reasonable speed limits.

The diaphragm motor 22 provides a further regulation should the tubes of the condenser become partially clogged up. In the event that passage of cooling water through the condenser is impeded by foreign matter,

an increased pressure is built up ahead of the propeller and this increase of pressure is, transmitted to the chamber 26 by the con: duit 28 connecting to the pressure-responsive device 22, causing the diaphragm 24 to 0 en the throttle valve 21 and stimulate the ow of cooling water through the condenser tubes.

While I have shown my invention in but circulating pump therefor, a turbine to drive said circulating pump, a throttling valve to control the supply of motive fluid to the turbine, two balance motors to actuate said throttling valve, means to render one motor responsive to variations in pressure within the condenser, and means to render the other motor responsive to variations in 'speed of the circulating pump.

2. In combination, a surface condenser, a turbine-driven circulating pump comprising turbine and pump units, a throttling valve to control the supply of motive fluid to the turbine unit, twobalance motors to actuate said throttling valve, means to render one motor responsive to variations of pressure in the condenser and variations of atmospheric pressure, and .means to render the other motor responsive to variations in pressure at the outlet of the circulating pump andto variations in speed of the pump.

3. In combination, a surface condenser, a turbine-driven circulating pump comprising turbine and pump units, a throttling valve to control the supply of motive fluid to the turbine unit, and controlling means for the throttling valve comprising a primary balance motor having a diaphragm, means to render one side of the diaphragm subject Inn to variations, in the ressure existing in the discharge outlet of t e pump, means to subject the other side of the diaphragm to pressures responsive to changes in speed of the pump, a secondarybalance motor having a diaphragm, means to render one side of the diaphragm responsive to variations in air pressure, and means to render the other side of the diaphragm responsive to variations in pressure within the condenser.

4. In combination with a surface condenser, a turbine-driven circulating pump,

a primary balance motor comprising a diaphragm connected to the throttling valve of the turbine and pressure chambers each side of the diaphragm, a conduit communicatin between one of said pressure chambers and the discharge outlet of the pump, a conduit communicating between the other pressure chamber and an auxiliarypump located within the inlet of the circulating pump, a secondary balance motor comprising a diaphragm connected to the throttling valve of the turbine and pressure chambers each side of the diaphragm, a conduit communicating between one of said pressure chambers and the atmosphere, and a conduit communicating between the other pressure chamber and the interior of the surface condenser.

5. In combination, a surface condenser, a circulating pump therefor, a turbine adapted to drive said circulating pump, a throttling valve to control the supply of motive fluid to the turbine, a primary balance motor comprising a diaphragm with a pressure chamber each side of-the diaphragm, a conduit communicating between one of said pressure chambers and the discharge outletof the circulating pump, a conduit communicating between the other pressure chamber and an auxiliary pump driven by the circulating pump, means to connect the diaphragm with the throttling "alve of the turbine to render the latter responsive to displacements of the diaphragm, a secondary balance motor comprising a'diaphragm with a pressure chamber each side of the diaphragm.

6. In combination with a condenser, a propeller circulating pump therefor, a turbine adapted to drive said circulating'pump, a supply inlet valvefor said turbine, automatic speed control means for said circulatingpump, comprising two pressure motor devices connected to said inlet valve, an auxiliary pump actuated by the turbine, a conduit communicating between said auxiliary' pump and a pressure control motor, a conduit communicating between said pressure motor and the outlet of the circulating pump, a conduit communicating between the condenser and a second pressure motor device having atmospheric pressure counteraction.

7. In combination, a condenser, a propeller pump associated .therewith, a pressure pump within the inlet of the propeller pump, a turbine to drive the pressure pump and the propeller pump, said propeller pump supplying a cooling fluid to the condenser, and pressure control means actuated by the pressure within the condenser, the'pressure pump, the pressure within theoutlet of the propeller pump and atmospheric pressure whereby a constant operation of the condenser is maintained.

8. The method of operating a condenser which comprises delivering steam thereto to be condensed, supplying cooling Water to the condenser to accomplish the condensation, and varying the supply of cooling water in response to the combined condi lions of pressure of the cooling water and of pressure within the condenser.

S). The method of operating a condenser which comprises delivering steam thereto to be condensed, supplying cooling water to the condenser to accomplish the condensation and increasing the supply of cooling water in response to resistance offered to the passage of cooling water through the condenser.

10. In combination, a surface condenser, means for supplying cooling water to the condenser, and means responsive to the combined conditions of the pressure of the cooling Water and of the pressure within'the condenser for regulating the supplyot' cooling Water.

11; In-combination, awsurface condenser, means for supplying cooling Water to the condenser, means responsive .to the resistance offered to the passage of cooling water through the condenser for regulating the supply of cooling water.

12. In combination, a surface condenser, means for supplying steam to be condensed to the condenser, means for supplying cooling water tothe condenser, and means responsive to the combined conditions of the pressure of the cooling water entering the condenserand of thepressure of steam Within the condenser for regulating the supply of cooling water.

In testimony whereof. I have hereunto subscribedmy name this 24th day of November, 1920.

HENRY F. SCHMIDT. 

